Automated production lines for rolled and welded ferrules

ABSTRACT

The invention is in the field of metallurgy and relates to an automatic machine for the continuous production of cylindrical shells from a pile of flat metal sheets. Said machine is characterized in that it is comprised of, from the output of the shell to the input of the metal sheet, a welding station provided with means for transferring and holding a rolled blank with jointed edges and means for the continuous formation of a welding bead along said edges, a station for the continuous transfer of the rolled blanks and for progressively tightening them, a station for the discontinuous transfer of the blanks to deliver them axially against each other, a rolling station consisting of a rolling machine, and a supply station comprising means for unpiling and transferring the metal sheets, and a servomechanism for adjusting the bending means as a function of the thickness of each sheet.

The present invention is in the metalworking field and has as itssubject matter an automatic machine for the continuous production offerrules from a stack of flat metal blanks.

A publication, FR2637206, by the applicant, has disclosed a machine,called a "rolling machine," having centering wheels enabling it toadjust in a precise manner to the rolling diameters; the description ofthis machine mentions that it is adapted to be associated with weldingmeans.

Also known from the applicant's older publication, viz., FR2528335, isthe association of a sensor with a machine for the purpose of measuringthe thickness of the metal blanks before they enter the machine, thissensor having a direct mechanical action on the bending wheels so as toadjust them to the required rolling diameter.

The latter machine, however, was not designed to be associated with anautomatic welding machine, and so the relatively imprecise action of thethickness sensor was satisfactory.

A first purpose of the invention is to propose an assemblage, called a"line," of means permitting metal blanks within thickness tolerances andof identical dimensions to be held, rolled and welded automatically(i.e., normally without human intervention).

To understand the technological background of the invention, publicationEP 0426258 (THOMASSEN) may be consulted, which describes a machine ofthis kind, comprising mainly means for bending the blanks, means for thediscontinuous transfer of the bent blanks, and welding means.

A problem of this machine is that the edges of the blanks are resistancewelded overlapping one another; the applications of the ferrulesobtained are limited for safety reasons since their strength is notsufficient to permit them to accommodate, if necessary, a product underpressure.

Also, a second purpose of the invention is to propose a machinesatisfying the first purpose mentioned, permitting the butt-welding ofthe rolled blanks in order to render the ferrules obtained capable ofaccommodating products under pressure.

The problem to be solved for the purpose of satisfying the secondpurpose is how to hold the rolled blanks in a position permitting themto be welded, while on the one hand holding the edges together, and onthe other hand keeping the end surfaces parallel.

It must be noted that, to satisfy both of these purposes, the commonproblem to be solved is to be found in the means for transferring theblanks from the rolling station to the welding station.

According to the invention, a machine for the automatic production ofcylindrical ferrules from metal blanks, which are to be welded withtheir edges joined, i.e., "butt-welded," said machine preferablycomprising a roller of the fluted roll type as described in theapplicant's publication FR2637206, is characterized mainly in that itcomprises the following, in an order beginning from the point of exit ofthe ferrules and going back to the point of entry of the blanks:

A welding station provided with means, called the first means,permitting the transfer of a rolled blank in a shape with its edgesabutting and assuring that this shape will be maintained, and means,called the second means, for forming a continuous welded seam along saidabutting edges,

at least one station, called the transfer and continuous constrictionstation, provided with means, called the third means, for moving therolled blanks on their longitudinal axis, and means, called the fourthmeans, simultaneously providing for the progressive constriction of theblank, so that, when it reaches the entry of the welding station, itwill be in a shape in which its edges are abutting,

at least one station, called the discontinuous .transfer station, havingmeans, called the fifth means, for moving a blank along its axis,

the rolling station constituted by a roller with rolls of the typereferred to above and

a station feeding the roller, and provided with means for picking blanksup from the stack, called the sixth means, or "pickers," and fortransferring the blanks one by one from a stack to the entrance to theroller, and a servomechanism for the fine control of the bending meanstaking into account the thickness of each blank to assure the preciseattainment of the diameter of the rolled blank with a precision on theorder of a millimeter.

From the assemblage of these means the result is that metal blanks ofordinary thickness tolerance can be rolled and welded in a continuousmanner without human intervention, the ferrules obtained being capableof accommodating a product under pressure.

In a preferred embodiment, in the first place, a supporting and guidingplate extends from the exit from the rolling station to the weldingstation through discontinuous and continuous transfer stations, thelongitudinal edges of the blanks being separated by the guide platealong which they can run, the guide plate becoming thinner past the exitfrom the rolling station; in the second place, said fifth means areconstituted by a mobile pusher running back and forth along the guideplate to move the blanks in a single direction from the roller to thecontinuous transfer station and, in the third place, said third meansare constituted by two sets of wheels, those of the first set beingsituated on the outside of the blanks and being the driving wheels urgedagainst those of the second set, the latter being situated inside of theblanks, said rollers of the first set being driven by motor meanscomprising a set of gears and so-called "cardan type" transmissionmeans.

Advantageously, said first means are constituted by a cage supported bythe frame of the machine, said cage being composed of twosemicylindrical parts, a bottom one and an upper one, the bottom partbeing fastened to the upper part by resilient means; said second weldingmeans can comprise particularly the T.I.G., M.A.G., M.I.G., plasma,submerged arc and laser processes, with support, and with or without aconsumable electrode. The second means comprise a nozzle supported onthe upper part of the cage and directed into the interior of the latter,said nozzle being provided with cooling means.

The result of this arrangement is that the resiliency of the cagepermits bringing the abutting edges fully against one another at theexit from the continuous transfer station and holding the blanks in thisshape during the welding operation.

According to a first variant, more particularly intended for makingferrules from blanks that are thick (between 1 and 5 mm, for example),in the first place, said fifth means are means for shifting a blankalong each time that a previously shifted blank has been introduced intothe continuous transfer station and for bringing the blank into axialabutment against the blank that preceded it in the station and, in thesecond place, said third means provide for the transfer of the blankswhile still pushing the blank present in the welding station.

In a second variant, more particularly intended for making ferrules fromblanks of lesser thickness (less than 1 mm), in the first place, saidfifth means are means for shifting a blank each time that a previouslydisplaced blank has been introduced into the welding station and hasbeen sufficiently welded to keep its end edges in parallel planes; inthe second place, said third means provide for the transfer of theblanks being welded one after the other and, in the third place, themachine has an additional transfer station situated between the rollingstation and the fifth means.

It is to be noted that the additional transfer station is intended toreduce the travel of the pusher of the discontinuous transfer station soas to provide for a maximum rate of advancement of the ferrules into thewelding station, the pusher being intended to lead a blank so as tobring it into contact with the preceding blank while the latter is stillpresent in the continuous transfer station and is being welded.

Preferably, the blanks are held suspended by the guide plate through thediscontinuous transfer station by means of a double set of wheels,between which the blanks are running, the wheels of each pair beingdisposed on either side of the guide plate, one of the sets beingsituated outside of the blanks and the other situated inside of theblanks; alternatively, the blanks could be supported by an elongatedcylindrical mandrel connected to the machine frame by the guide plate.

According to an advantageous embodiment, the frame is composed of aplurality of interconnected separable units, each unit bearing astation.

The result of this arrangement is that the various stations of themachine can be separated, so as to facilitate repairs, for example, andto change the various transfer stations to obtain one or the other ofsaid variants of the machine.

The present invention will be better understood and details relatingthereto will appear in the description now to be given of preferredembodiments, in connection with the figures in the annexed drawings,wherein:

FIG. 1 is a overall view of the principal stations constituting amachine of the invention, including two variant embodiments,

FIG. 2 is a simplified perspective view of a machine of the inventionaccording to a first embodiment more particularly intended for theproduction of ferrules from thick metal blanks,

FIGS. 3 and 4 are diagrammatic representations of a discontinuoustransfer station of the invention, in perspective and in an end view,respectively,

FIGS. 5 and 6 are diagrammatic representations of a continuous transferstation of said first variant, in perspective and in an end view,respectively,

FIG. 7 is a partially cut-away view of a welding station of said firstvariant.

FIG. 8 is a diagrammatic, partially cut-away perspective view of awelding station and of a continuous transfer station according to asecond variant of the invention, which is more particularly intended forthe production of short ferrules from thin blank metal.

In FIG. 1, a ferrule production line according to the invention ingeneral has mainly five stations, that is, in the direction of themovement of the material being processed: a feeder station 2, a roller 4with fluted rolls (FR2637206), a discontinuous transfer station withpusher forming said fifth means, a continuous transfer station 8provided with said third transfer means and means called fourthconstriction means and, lastly, a welding station 10. In one variant,the discontinuous transfer station 6 comprises, on the one hand, saidfifth means and, on the other, an additional transfer station 7 of themotorized wheel type, intended, if need be, to limit the travel of thepusher, as will be explained further on.

The servomechanism 12 of the roller 4 comprises a thickness detector 14putting out a thickness signal, a computer means 16 receiving saidthickness signal and putting out binary signals, a stepper motor 18receiving said binary signals to govern the separation of the rolls andthus the rolling radius.

In FIG. 2 it will be noted that the feeder station 2 is constitutedmainly by a transfer track 20 for a carriage 22 with suction cups 24acting to pick up the stacked flat blanks, and that the welding means 28are of the arc welding type, with support 104 (FIG. 7) or 106 (FIG. 8)and electrode 108.

Returning to FIG. 1, the thickness detector 14 is situated on thetransfer path 20 of the blanks 26. Said thickness detector 14 is amechanical gauge of the "Palmer" type, measuring the thickness of theblank 26 at one point. In the variant shown, the detector 14 is disposedsubstantially vertically above the transfer path 20, and that the edgeof the blank 26, on which the measurement is made, is the transverseedge, which will be the first to pass between the rolls of the roller 4.

A supporting and guiding plate 30 extends from the exit from the rollingstation 4 to the welding station 10 along the discontinuous andcontinuous transfer stations 6 and 8. The butt joints of the blanks areheld apart and guided by the guide plate 30, along which they can run,said guide plate 30 thinning from, for example, 12 mm down to 1.4 mmfrom the exit of the rolling station 4 for blanks of a thickness between1 and 5 mm and from 12 to 0.2 mm for blanks less than 1 mm thick.

In FIGS. 2, 3 and 4, the discontinuous transfer station 6 comprises apusher 32, which can be reciprocated back and forth along the guideplate 30 to move the blanks in only one direction from the roller 4toward the continuous transfer station 8. The pusher 32 comprises acarriage 34 running along the guide plate 30 and driven by pneumaticmeans, such as a horizontal jack not shown. The carriage 34 supports apusher finger 36 which can be retracted by a jack 38; the finger 36 iseither retracted during the "return" movement or it is in the activeposition during the "forward" movement. The running of the carriage 34is controlled from a control cabinet not shown.

The continuous transfer station of FIGS. 2, 3 and 4 is also applicableto the second variant, with four fingers (fingers 80, FIG. 8) thrustingagainst both sides of the blank at its upper and lower areas, for thepurpose of holding ferrules of thin metal so that their end surfaces arein parallel planes; the four fingers are retractable laterally to permitthe carriage 34 to return toward the exit of said additional transferstation 7.

Continuous transfer and welding stations of a first variant of themachine are represented in FIGS. 5 to 7. In this variant, the pusher 32displaces a blank each time that a blank previously displaced has beenintroduced into the continuous transfer station 8: the blank is thrustaxially against the blank that preceded it in the station 6, and thecontinuous transfer means provide for the transfer of the blanks whilepushing the present blank into the welding station 10.

Similar stations of a second variant of the machine are shown in FIG. 8.In this variant the pusher 32 holds the blank that is being welded untilit has been sufficiently welded, on a length of about one centimeter,for example, so as to keep its end surfaces in parallel planes; then thepusher 32 goes to find the next blank at the exit of the additionaltransfer station 7 so as to bring it into contact with the blank beingwelded, while the continuous transfer means provide for the transfer ofthe successive blanks that are being welded. Advantageously, theadditional transfer station 7, shown schematically in FIG. 1, isinserted between the exit from the roller 4 and the discontinuoustransfer station 6, in order to shorten the stroke of the movable pusher32 and, lastly, to increase the working rate of the machine.

In FIGS. 5, 6 and 8, the third, continuous transfer means areconstituted by a double set 40 and 42 of wheels, the wheels of the firstset 40 being situated on the outside of the blanks and being drivewheels urged against the wheels of the second set 42, the latter beingsituated on the inside of the blanks. The drive wheels 40 are powered bydrive means comprising gears 44 and transmission means 46 known as"cardan shafts." Preferably, the diameter of the drive wheels 40situated at the entrance to the continuous transfer station 8 isslightly greater than the diameter of the drive wheels 40 followingthem, any possible spacing between two successive blanks being thuscorrected due to this difference in diameter. It will be noted in FIG. 6that the inside wheels 42 have a flange 48 emerging from between theedges of the blanks in the prolongation of the guide plate 30 for thepurpose of guiding those edges.

In FIGS. 2, 5 and 6, the fourth means, the progressive constrictionmeans, are constituted by a plurality of longitudinal bars, such as 50,provided with wheels, such as 52, tangent to an envelope 54 (FIG. 1) orsurface that is very slightly tapering. Said bars 50 are supported atleast at one of their extremities by cam-action means for bringing themnearer to or farther away from the axis of said envelope 54. Thecam-action means are used to provide for variations in the nominaldiameter of the ferrules.

According to a first embodiment, the variations are discontinuous, whichcorresponds to ball bearing cams, with manual adjusting means: thecam-action means comprise jacks, such as 56, the shafts 58 of which areconnected respectively to the bars 50, the stroke of the jacks 56 beinglimited by means of a set 60 of invertible abutments 62: the abutments62 are supported by a ring 64, which can pivot around the axis of saidenvelope 54, to be placed facing their respective jack 56 according tothe desired nominal diameter.

In another embodiment not shown in the Figures, the variations could becontinuous, which would correspond to a cam, such as a ramp that iscontinuously progressive, with motor-driven means of variation.

In FIG. 7, the first means, for keeping butt joints edge to edge whilebeing welded, are constituted by a cage 66 supported by the frame 68 ofthe machine, said cage 66 being composed of two semicylindrical parts 70and 72, the one 72 being the lower one and the other 70 the upper.

The lower part 72 is connected to the upper part 70 by resilient means74 making it possible, in spite of any diameter differences in theblanks, to bring the lateral edges of the blanks into contact at theexit from the continuous transfer station 8.

Note the presence of a plurality of sets, such as 78, of wheels, such as76, supported by each of the lower 72 and upper 70 parts of the cage,each set 78 of wheels extending along a generatrix of the cage 66.

In FIG. 8, a cage 67 is similar to cage 66 shown in FIG. 7, said cage 66extending in the direction from the discontinuous transfer station 6,said prolongation containing the third (40, 42) and fourth means.

So, whereas in FIGS. 5 and 6 the set of drive wheels 40 is supported bythe guide plate 30 and the set of inside wheels 42 is supported by amandrel 82 itself supported by the guide plate 30, it will be noted inFIG. 8 that the set of drive wheels 40 is supported by the cage 67 andis divided into two groups 84 and 86, the one 84 supported by cage 67 inits lower area, the other 86 in its upper area.

One of the sets of wheels 40 and/or 42 is provided with elastic means 88designed to apply pressure against the other set of wheels. In FIG. 8,it is the inside wheels 42 that have said elastic means 88 whereas, inFIGS. 5 and 6, it is the drive wheels 40.

In FIG. 8, the fourth means are constituted, on the one hand, by aplurality of groups, such as 90, of wheels, such as 92, of thehyperboloidal type, also called "diabolo" wheels, said wheels 92conforming to the outside surface of the blanks 1. The sets of "diabolo"wheels 92 are respectively supported by the cage 67 through the mediumof means 194 for controlling their tangency to said adjacent conicalsurface 54. It will be noted that the resilient connection 74 in FIG. 7between the two upper 70 and lower 72 parts of the cage 67 is part ofthe fourth means.

It will be noted that FIG. 2, on the one hand and, FIGS. 3 and 4, on theother, show different means for supporting the blanks 1 along thediscontinuous transfer station 6:

In FIG. 2, the continuous transfer station 8 and the discontinuoustransfer station 6 have each an elongated cylindrical mandrel 94connected to the frame by the guide plate 30, said mandrel beingdesigned to support the rolled blanks 1, the longitudinal edges of whichare separated by said guide plate 30 along which they can run. Themandrels 94 are situated in the prolongation of the supporting roll ofthe roller 4 and of its bearing;

In FIGS. 3 and 4, the blanks 1 are suspended from the guide plate 30along the discontinuous transfer station 6 by means of two sets 96 and98 of pairs of wheels, such as 100 and 102, between which the blanks 1are running: the pairs of wheels 100 and 102 are disposed one on eitherside of the guide plate 30, some of them, 100, being situated on theoutside of the blanks 1, the others, 102, on the inside of the blanks.

It will be furthermore noted that the shared support of the two meanscan be either a knurled wheel 104 as shown in FIG. 7 or an anvil asshown in FIG. 8. A nozzle 110 is supported in the upper part 70 of thecages 66 and 67, said nozzle being equipped with cooling means 114.

Advantageously, the nozzle 110 is made of bronze and the blanks 1 arepressed against the inside face of the nozzle 110 by resilient means 74connecting together the lower part 72 and upper part 70 of cages 66 and67.

At the exit of the machine, the ferrules can be separated from oneanother either manually by an operator or mechanically by motor-drivenmeans contained in a connected machine.

I claim:
 1. Machine for the automatic production of cylindrical ferrulesby rolling and welding flat metal pieces, said machine comprisingawelding station provided with means enabling the transfer of a rolledblank and with continuous welding means, at least one transfer stationprovided with means enabling the transfer, along their longitudinalaxis, of rolled blanks and with means simultaneously enabling theprogressive constriction of the blank to bring it, when it arrives atthe entry of the welding station, into the shape for welding, a rollingstation constituted by a rolling machine with rolls and comprising meansfor discharging a blank along its axis, and a rolling machine feederstation, provided with means for picking up flats from a stack one byone and transferring them to the entry of the rolling machine,characterized:in that one said transfer station comprises fifth meansfor displacing a blank each time that a previously displaced blank hasbeen introduced into the transfer station, and for keeping its endsurfaces in parallel planes, and bringing one end of a blank into axialcontact against the end of the blank that has preceded it in thestation, in that one said transfer station for the rolled blankscomprises third means for bringing the blanks to the entry of thewelding station, and fourth means for putting the blanks into abutt-joined shape,in that first means are constituted by a cagesupported by the frame of the machine, said cage being composed of twosubstantially semicylindrical parts, one the lower part and the otherthe upper part, the lower part being joined to the upper part byresilient means, by means of which it is possible to perform the weldingbetween said butt-joined edges by forming a welded seam since, on theone hand, these edges are butted together and, on the other, there is nospace separating the ends of two consecutive ferrules in the weldingstation.
 2. Machine according to claim 1, characterized in that saidcontinuous welding machines comprisesmeans called second meanscomprising a nozzle supported on the upper part of the cage and pointinginto the internal zone of the latter, said nozzle, being provided withcooling means.
 3. Machine according to claim 1, characterized in thatsaid station for feeding flat metal pieces comprises:a transfer path fora carriage with suction cups serving as an unstacker of stacked flatmetal pieces, a thickness detector measuring the thickness of a metalpiece at one point, the thickness detector being disposed substantiallydirectly above the transfer path, the edge of the metal piece, on whichthe measurement is performed, being the transverse edge, which Willfirst penetrate between the rolls of the rolling machine, and in that,the rolling machine being of the fluted roll type, a servomechanism forthe fine control of the rolling means takes into account the thicknessof each piece to enable, with precision, the obtaining of a rolled blankwith a precision on the order of a millimeter.
 4. Machine according toclaim 3, characterizedin that a guide plate extends from the exit of therolling station up to the welding station along the continuous anddiscontinuous transfer stations, the longitudinal edges of the blanksbeing held apart by the guide plate becoming thinner past the exit ofthe rolling station, in that said fifth means are constituted by apusher reciprocating along the guide plate to move the blanks in onedirection from the rolling machine toward the continuous transferstation, said pusher being constituted by a carriage running along theguide plate by virtue of pneumatic means and supporting at least oneretractable pusher finger, said finger being either retracted during thereturn movement or placed in the working position during the outwardmovement corresponding to the movement transferring blanks from therolling station up to the continuous transfer station, and in that saidthird means are constituted by a double set of wheels, those of thefirst set being situated outside of the blanks and being driving wheelsurged against those of the second set, the latter being situated outsideof the blanks, said wheels of the first set being driven by drivingmeans comprising a gear box and transmission means defined as cardanshafts, any one of said sets being equipped with resilient means forapplying said pressure on the blanks against the other set of wheels,the wheels of the second set having a flange emerging from between theedges of the blanks in the prolongation of the guide plate for thepurpose of guiding them.
 5. Machine according to claim 4,characterized:in that the first set of wheels of the third means issupported by the guide plate, the second set of wheels of the thirdmeans being supported by a mandrel itself supported by the guide plate,in that the fourth means are constituted by a plurality of longitudinalbars provided with wheels tangent to a nearby tapering surface of thecylinder, said bars being supported at least at one of their extremitiesby camaction means to draw them away or bring them toward said taperingsurface, and in each of the parts, lower and upper, of said cageconstituting the first means is provided with a plurality of groups ofequally distributed wheels, each group of wheels extending along ageneratrix of the cage.
 6. Machine according to claim 5,characterized:in that the first set of wheels of the third means issupported by the guide plate, the second set of wheels of the thirdmeans being supported by a mandrel, itself supported by the guide plate,in that the fourth means are constituted by a plurality of longitudinalbars provided with wheels tangent to a nearby tapering surface of thecylinder, said bars being supported at at least one of their extremitiesby cam-action means to move them away from or toward said taperingsurface, and in that each of the parts, lower and upper, of said cageconstituting the first means is provided with a plurality of groups ofequally distributed wheels, each group of wheels extending along ageneratrix of the case.
 7. Machine according to claim 6,characterized:in that the carriage of the discontinuous transfer stationis provided with at least four fingers distributed on both sides of theguide plate and designed to be in contact with the blank it its lowerand upper zones, the retraction of the fingers being performedlaterally, in that the cage is prolonged in the direction of thediscontinuous transfer station, said prolongation containing said fourthand third means, in that the two sets of wheels of the third means issupported by the cage and is divided into two groups, one supported inthe lower area of the cage, the other in the high area, and in that thefourth means are constituted, on the one hand, by a plurality of sets ofhyperboloidal wheels, said wheels conforming to the outer surface of theblanks, the groups of wheels being respectively supported by the cagevia means of controlling their tangency to said nearby tapering surfaceof the cylinder and, on the other, by the resilient coupling between thetwo set upper and lower parts of the cage.
 8. Machine according to claim7, characterized:in that the blanks are supported along thediscontinuous transfer station by an elongated cylindrical mandrelconnected to the frame of the machine by the guiding plate.
 9. Machineaccording to claim 8, characterized:in that the blanks are heldsuspended by the guide bar along the discontinuous transfer station bymeans of a double set of pairs of wheels, between which the blanks run,the wheels of each pair being disposed one on each side of the guideplate, one of the sets being situated outside of the blanks and theother being situated inside of the blanks.
 10. Machine according toclaim 9, characterized in that the various stations are separable fromone another.